By Rick Reeno

Before he even steps in the ring on Saturday night, WBA 'regular' welterweight champion Keith 'One Time' Thurman (25-0, 21KOs) has been ruled out as a potential September 12th opponent for WBC/WBA full champion Floyd Mayweather Jr. (48-0, 26KOs).

Thurman will defend his title against former champion Luis Collazo (36-6, 19KOs) at the USF Sundome in Tampa, Florida. The match headlines the ESPN debut of Premier Boxing Champions   (PBC).

Mayweather has mentioned the likes of Andre Berto and Karim Mayfield as possible candidates for the fall. Very few (if any) expect either man to secure the assignment. A more likely opponent is former champion Amir Khan (31-3, 19KOs) of Bolton.

September 12th is just around the corner. Could Thurman actually make such a quick turnaround?

"Yes I could, especially if it ends early. If it's an early knockout I definitely could," Thurman said.

But, Mayweather Promotions CEO Leonard Ellerbe recently stated that 'nobody is even thinking about' Thurman.

"I want him whenever he wants me. Whenever he's ready. I think it's a fan friendly fight. I have one opponent that's in common with Mayweather right now, Robert Guerrero. And I look forward to having many other opponents in common with Mayweather, so I can show how I look in the ring in comparison with some of the other top welterweights," Thurman said.